package NEWKE;

public class OJ {
    public ListNode Merge(ListNode list1,ListNode list2) {
        if(list1==null){
            return list2;
        }
        if(list2==null){
            return list1;
        }

        ListNode dummyHead=new ListNode(-1);
        ListNode node=dummyHead;
        while (list1!=null && list2!=null) {
            if (list1.val <= list2.val) {
                node.next=list1;
                node=list1;
                list1 = list1.next;
            } else {
                node.next=list2;
                node=list2;
                list2=list2.next;
            }
            if(list1==null){
                node.next=list2;

            }
            if (list2==null){
                node.next=list1;
            }
        }

        return dummyHead.next;


    }

}
